Just a little project Im making.
It is acceleratable (UP key), and the balls duration is adjustable.
Spawn fuel with F. Have fun, and use it if you want! Im making a simple car right now, but even if I use entity.vel or a custom vel, the balls get fired off the cylinder. Just wait!

Pretty stable, with a lot of speed drops when accelerating, but who cares? Flywheels solve this.
Use it if you want, dont give credit, but no warranty: you make it work!
It starts automatically after pressing play.
Made in 2.0.2b15, tell me if it doesnt even work!